(1) “Commission” means the Tennessee public utility commission;

(2) “Federal safety standards” means the minimum federal safety standards adopted by the United States department of transportation pursuant to the Natural Gas Pipeline Safety Act (49 U.S.C. § 60101 et seq.) or any amendments thereto which may be adopted in the future;

(3) “Gas” means natural gas, petroleum gas, flammable gas, or gas which is toxic or corrosive;

(4) “Gas public utilities” means any person, firm, corporation or other legal entity of any kind engaged in the transportation of gas, and includes the state of Tennessee, every county in the state of Tennessee, every municipality in the state of Tennessee and every utility district created under title 7, chapter 82, which has not been certified with the department of transportation under the Natural Gas Pipeline Safety Act, every public body or corporation of whatever kind in the state of Tennessee, and every private or nonpublic entity, when engaged in the transportation of gas;

(5) “Pipeline systems” means new and existing pipeline rights-of-way and any pipeline, equipment facility, and building, used by a public utility in the transportation and distribution of gas or the treatment of gas during the course of transportation and distribution, but “rights-of-way” as used in §§ 65-28-104 — 65-28-111 does not authorize the commission to prescribe the location or routing of any pipeline facility; and

(6) “Transportation of gas” means the gathering, transmission, and distribution of natural gas by pipeline, or its storage, and the transmission and distribution of all kinds of gas other than natural gas.